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Urine Methylmalonate/Creatinine Ratio — Turbidimetric Creatinine Measurement

Published: August 9, 2026Updated: August 16, 2026

A urine test measuring methylmalonic acid relative to creatinine to help evaluate possible vitamin B12 deficiency or methylmalonic acidemia.

Quick summary

["An elevated urine MMA-to-creatinine ratio may suggest vitamin B12 deficiency or another cause of increased methylmalonic acid and requires clinical interpretation."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
110569-1
Short code
Methylmalonate/Creat Msmt Ur
Synonyms
Methylmalonate/Creat Msmt Ur
Category
kidney
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

What is this test?

This test measures methylmalonic acid (MMA) in urine and compares it with the amount of creatinine. Creatinine is used as a marker of urine concentration, so the ratio can help account for variations in how dilute the urine is.

Why might I need this test?

The test may be used to investigate a vitamin B12 deficiency or when an increased MMA level raises concern for methylmalonic acidemia, an inherited metabolic condition. It may also be used alongside blood tests and other clinical findings.

How is the test performed?

A urine sample is collected according to the laboratory's instructions. The laboratory measures methylmalonate and creatinine and calculates their ratio. Creatinine is often measured by turbidimetry, while methylmalonate is measured using a separate validated laboratory method.

How do I prepare for the test?

Follow the urine collection instructions provided by your healthcare professional, including the collection time and container. Inform the clinician about vitamin supplements, recently taken antibiotics, pregnancy, and kidney problems, and do not stop prescribed medicines or supplements without medical advice.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Urine MMA/Creatinine ratio

Frequently asked questions

Why is the result reported as a ratio?
Urine can vary greatly in concentration. Comparing MMA with creatinine helps reduce the effect of urine dilution or concentration on the result.
Does this test diagnose vitamin B12 deficiency?
No single urine result confirms vitamin B12 deficiency. Your clinician will interpret it with your symptoms, blood vitamin B12 level, serum MMA, and sometimes homocysteine.
What can affect the urine MMA-to-creatinine ratio?
Kidney function, certain antibiotics, vitamin supplements, hydration, and urine collection quality may affect the result. Tell your clinician about medications and supplements before testing.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy